Electronic circuits, such as electronic circuits including two or more circuit packages, can be used for logic processing, memory storage, or both. Circuit packages can include one or more chips, such as silicon chips, comprising a plurality of electronic circuits and also referred to as “integrated circuits”. For instance, integrated circuits can be used in personal computers, servers, game counsels, internet-of-things devices, and other electronic devices. Datacenter, server, and client device markets seek integrated circuits with higher performance, compact size, and reduced power consumption.
With increasing computing demand, electronic circuits often include multiple chips. For instance, a plurality of chips can be stacked on one another within a circuit package to provide more processing and memory capacity, sometimes referred to as “stacked-die products”. However, when combined in this manner, manufacturing flexibility is reduced, because the processor and memory are combined and because it may be difficult to test the memory separately from the processor, which means that testing can only occur after the chips are stacked.
As an alternative to stacked-die products, separate circuit packages can be stacked (e.g., package on package or “PoP”) to reduce the amount of board space used to couple the electronic circuit to a printed circuit board (PCB) or substrate of a larger circuit package. However, there is often unused space within stacked circuit packages and additional space must be allowed to create electrical connections between the packages.
Electrical connections (also referred to herein as, “electrical contacts”) between stacked circuit packages are often located alongside a chip, for instance, around the perimeter of the chip. The electrical pads of an upper circuit package (also referred to herein as “upper package”) and lower circuit package (also referred to herein as “bottom package” or “bottom circuit package”) can be specially configured for the stacked arrangement. For instance, the contacts of the upper circuit package may be arranged in an area corresponding to locations around the exterior perimeter of the bottom circuit package. A substrate of the upper or lower circuit package can include dimensions large enough to accommodate the chip foot print and the electrical connections.
Passive electrical components are also commonly included in circuit packages. As used herein, “passive electrical component” refers to, for example, through mold vias (TMVs), resistors, capacitors, magnetic (inductive) devices, transducers, detectors, antennas, and other power delivery, management, or transmission components that are generally incapable of controlling current by means of another electrical signal. Among passive electrical components, legacy TMVs formed, for example, by laser drilling commonly have a cone-shaped cross section when viewed from an elevation perspective.
Electrical connections between two circuit packages and from a circuit package to a PCB or motherboard may be provided by, for example, a ball grid array, a pin grid array, TMVs, and the like.
In some instances, techniques to form voids in a circuit package, such as laser drilling, mechanical drilling, chemical or vapor etching and the like may cause defects and increase fabrication costs.